The U.S. logged the highest number of COVID-19 deaths in two weeks, a new NBC News tally showed Thursday, but widespread testing shortages raised concerns that the figures coming out of the hardest-hit states might not be presenting a true picture of this deadly pandemic. The 1,424 fatalities reported Wednesday were the highest since July 28, when 2,218 deaths were reported, the figures showed. And it was the twelfth time in the last 16 days that the death toll exceeded 1,000.